In internal combustion engines, particularly where the engine is of a high compression type (e.g. diesel) sealing problems with the head gasket are oftentimes encountered. One of the principal causes contributing to this problem is the uneven clamping or compressive forces which are exerted on the gasket by the assembled head. It is common in engines of this general type for the head fasteners to be primarily located in the marginal areas of the cylinder head with the result that there are wide areas of the gasket, particularly between adjacent cylinder ends in the engine block, which are disposed at substantial relative distances from the fasteners and thus, the clamping forces exerted on these wide areas by such fasteners are diminished as compared to other areas of the gasket. Because of these non-uniform clamping forces serious sealing problems are encountered due, for example, to excessive gasket wear.
Various attempts at correcting this problem have been tried in the past; however, because of certain inherent design characteristics, they have been beset with one or more of the following shortcomings: (a) special gaskets were utilized which were of costly complex design; (b) special machining of the gasket engaging surfaces of either the cylinder head or engine block or both was required; (c) relocating of the fasteners relative to the cylinder ends was a costly and time-consuming operation; and (d) increasing the number of fasteners and locating them in areas other than the marginal portion, required special tools, fixtures and molds and such additional fasteners frequently created obstructions within the cooling jacket surrounding the cylinders in the engine block.